鼠伤寒沙门氏菌asd基因的克隆及序列分析

Cloning and sequencing of the asd gene of Salmonella typhimurium

以鼠伤寒沙门氏菌标准株基因组DNA作为模板,用PCR的方法扩增鼠伤寒沙门氏菌的asd基因并克隆入质粒pUC19,并对其进行测序,序列与文献报道一致。同时将质粒pYA248上的链球菌asd基因进行了置换,观察了分别含有链球菌asd基因与鼠伤寒沙门氏菌asd基因的质粒在减毒鼠伤寒沙门氏菌X4072中的生长情况,结果表明含有鼠伤寒沙门氏菌的asd基因的高拷贝质粒pUC19的菌株生长情况更好。为完善染色体/质粒平衡致死系统,构建减毒鼠伤寒沙门氏活菌疫苗奠定了基础。

The asd gene from Salmonella typhimurium was obtained by PCR and sequencing.The asd gene was cloned into plasmid pUC19which was named the plasmid pZL21.At the same time replacing the asd gene located in the vector pYA248containing the wild-type asd gene from Streptococcus with the asd gene from S.typhimurium.Comparing the growth of S.typhimurium X4072containing those vactors.Results showed S.typhimurium X4072(pZL21)grown better than X4072(pYA248).This work will help to improve a balanced-lethal system,to develop liver attenu-ated S.ty phimurium vaccine strains.